Apparatus and method for transmitting and receiving an information symbol in a visible light communication system for color code modulation

An apparatus for transmitting an information symbol using a constellation defined corresponding to a modulation scheme on a chromaticity diagram of a visible light communication system, comprising:

• a color coding block for determining a first coordinates value corresponding to the information symbol to be transmitted on the chromaticity diagram;
• a coordinates calculator for determining a first color ratio corresponding to the first coordinates value, determining a second coordinates value corresponding to a compensation symbol for compensating for the first color ratio into a color white, and determining a second color ratio corresponding to the second coordinates value;
• and
• a light emitting unit for emitting a visible ray corresponding to each of the first color ratio and the second color ratio,
• wherein the first and the second coordinates values are located on a line in the chromaticity diagram.

A method for receiving an information symbol using a constellation defined corresponding to a modulation scheme on a chromaticity diagram of a visible light communication system, the method comprising the steps of:

• filtering a visible ray corresponding to a compensation symbol among visible rays transmitted from a transmission apparatus;
• receiving the visible ray corresponding to the information symbol;
• converting the visible ray into an electric signal;
• determining a coordinates value corresponding to a color ratio of the electric signal on the chromaticity diagram;
• and
• decoding symbol information corresponding to the coordinates value,
• wherein the compensation symbol has a color ratio for compensating the color ratio of the information symbol into a color white on the chromaticity diagram, and
• wherein the information symbol and the compensation symbol are located in a line in the chromaticity diagram.

An apparatus for receiving an information symbol using a constellation defined corresponding to a modulation scheme on a chromaticity diagram of a visible light communication system, comprising:

• an optical filter for filtering a visible ray corresponding to a compensation symbol among visible rays transmitted from a transmission apparatus and receiving the visible ray corresponding to the information symbol;
• a light reception unit for converting the visible ray into an electric signal;
• an RGB calculator for determining a coordinates value corresponding to a color ratio of the electric signal on the chromaticity diagram;
• and
• a decoding block for decoding symbol information corresponding to the coordinates value,
• wherein the compensation symbol has a color ratio for compensating the color ratio of the information symbol into a color white on the chromaticity diagram, and
• wherein the information symbol and the compensation symbol are located in a line in the chromaticity diagram.

A method for receiving an information symbol using a constellation defined corresponding to a modulation scheme on a chromaticity diagram of a visible light communication system, the method comprising the steps of:

• converting a visible ray transmitted from a transmission apparatus into an electric signal;
• identifying if the electric signal is an information symbol or a compensation symbol, based on a coordinates value corresponding to a color ratio of the electric signal in the chromaticity diagram;
• and
• decoding the information symbol,
• wherein the compensation symbol has a color ratio for compensating the color ratio of the information symbol into a color white on the chromaticity diagram, and
• wherein the information symbol and the compensation symbol are located in a line in the chromaticity diagram.

An apparatus for receiving an information symbol using a constellation defined corresponding to a modulation scheme on a chromaticity diagram of a visible light communication system, the method comprising the steps of:

• a light reception unit for converting a visible ray transmitted from a transmission apparatus into an electric signal;
• an RGB calculator for identifying if the electric signal is an information symbol or a compensation symbol based on a coordinates value corresponding to a color ratio of the electric signal in the chromaticity diagram and outputting the information symbol;
• and
• a decoding block for decoding the information symbol,
• wherein the compensation symbol has a color ratio for compensating the color ratio of the information symbol into a color white on the chromaticity diagram, and
• wherein the information symbol and the compensation symbol are located in a line in the chromaticity diagram.